Triethylamine → 1-[(4-Methoxy)phenyl]-3-(hydroxymethyl)-1H-pyrazole 5-(methoxycarbonyl)pyrazole

Participants

Reaction Steps

To a solution of 1-[(4-methoxy)phenyl]-1H-pyrazole-5-(methoxycarbonyl)pyrazole-3-carboxylic acid (2.4 g, 8.69 mmol) in 50 mL of tetrahydrofuran at−20° C. was added triethylamine (1.21 mL, 8.69 mmol) and ethyl chloroformate (0.83 mL, 8.69 mmol). This mixture was stirred for 30 min and then there was added sodium borohydride (0.66 g, 17.4 mmol) in a minimal amount of water. The reaction mixture was stirred with slow warming to room temperature for 1 h and then was quenched with 10% aq HCl. After diluting with ethyl acetate, the organics were washed with brine, dried (MgSO4) and concentrated in vacuo. The residue was purified by flash chromatography (elution with 3:2 ethyl acetate/hexane) to afford 1.4 g (61%) of the title compound. LRMS (DCI): 263.3 (M+H)+.

Provenance & Evidence